IP Routing Features

UDP Broadcast Forwarding

Operating Notes for UDP Broadcast Forwarding

Maximum Number of Entries. The number of UDP broadcast entries and IP helper addresses combined can be up to 16 per VLAN, with an overall maximum of 2048 on the switch. (IP helper addresses are used with the switch’s DHCP Relay operation. For more information, refer to “Configuring DHCP Relay” on page 7-26.)For example, if VLAN 1 has 2 IP helper addresses configured, you can add up to 14 UDP forwarding entries in the same VLAN.

TCP/UDP Port Number Ranges. There are three ranges:

Well-Known Ports: 0 - 1023

Registered Ports: 1024 - 49151

Dynamic and/or Private Ports: 49152 - 65535

For more information, including a listing of UDP/TCP port numbers, go to the Internet Assigned Numbers Authority (IANA) website at:

www.iana.org

Then click on:

Protocol Number Assignment Services

P (Under “Directory of General Assigned Numbers” heading)

Port Numbers

Messages Related to UDP Broadcast Forwarding

Message

Meaning

 

 

udp-bcast-forward: IP Routing

Appears in the CLI if an attempt to enable UDP broadcast

support must be enabled first.

forwarding has been made without IP routing being enabled first.

 

Enable IP routing, then enable UDP broadcast forwarding.

UDP broadcast forwarder feature

UDP broadcast forwarding has been globally enabled on the router.

enabled

Appears in the Event Log and, if configured, in SNMP traps.

 

 

 

UDP broadcast forwarder feature

UDP broadcast forwarding has been globally disabled on the

disabled

routing switch. This action does not prevent you from configuring

UDP broadcast forwarding addresses, but does prevent UDP

 

broadcast forwarding operation. Appears in the Event Log and, if

 

configured, in SNMP traps.

UDP broadcast forwarder must be disabled first.

Appears in the CLI if you attempt to disable routing while UDP forwarding is enabled on the switch.

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